html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
  }

  nav ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
  }
  
  nav li {
    margin-right: 10px;
  }
  
  nav li:last-child {
    margin-right: 0;
  }
  
  nav a {
    color: #333;
    text-decoration: none;
  }
  
  form {
    display: flex;
    align-items: center;
  }
  
  input[type="text"] {
    flex: 1;
    margin-right: 10px;
    padding: 5px;
    border: none;
    border-radius: 3px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  }
  
  button {
    padding: 5px 10px;
    border: none;
    border-radius: 3px;
    background-color: #333;
    color: #fff;
    cursor: pointer;
  }
  
  button:hover {
    background-color: #555;
  }

  header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 5px;
    background-color: #f5f5f5;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    height: 60px; /* Set the height of the header */
  }
  
  main {
    height: calc(100% - 60px); /* Set the height of the main element to fill the remaining space */
    overflow: hidden;
  }
  
  iframe {
    width: 100%;
    height: 100%; /* Set the height of the iframe to fill the main element */
    border: none;
    overflow: hidden;
  }
  
  .iframes {
    height: 100%;
  }
  .tab.active {
    background-color: #ccc;
  }